Shuttle Discovery Delivered Station Hub in 2007

On October 23, 2007, the space shuttle Discovery launched to deliver the Harmony module to the International Space Station. This flight, designated STS-120, delivered a utility hub that increased the station's physical footprint. The module measured 14 feet wide and 24 feet long, a size comparable to a minibus.

The installation of Harmony shifted the station's scale from the size of a three-bedroom house to that of a five-bedroom house. The module serves as a central connection point for the European Space Agency's Columbus laboratory and Japan's Kibo laboratory. It also houses the sleeping quarters for American astronauts and holds eight payload racks, with four reserved for avionics and four for stowage or crew quarters.

Astronauts initially attached the module to the Unity node for a temporary hold. After the shuttle departed, the crew used the station's robotic arm to move the shuttle docking port located on the Destiny module. This action cleared the forward port of Destiny, allowing the crew to berth Harmony at its permanent location. From there, it became the structural link for the Columbus and Kibo modules on the station's starboard and port sides, respectively.

Harmony, originally designated Node 2, was built by Italy-based Thales Alenia Space for NASA. It followed Unity, or Node 1, as the second NASA-led hub module for the outpost. The module features five common berthing mechanisms that act as connection points for other hardware. A docking port on its roof also provides a parking spot for visiting vehicles. The name Harmony was selected through a public naming contest run by NASA.

The arrival of Harmony marked a new phase in the station's construction. Before this delivery, the last new room added to the station was Russia's Pirs docking module in 2001. Pirs has since been discarded. The STS-120 mission lasted approximately two weeks, during which the crew completed the necessary repositioning tasks to secure the new hub.